It's definitely a growing problem with Rust. I have noticed my dependency trees growing from 20-50 a few years ago to usually 200-500 now.
It's not quite as bad as NPM yet, where it can easily get into the low thousands. Also the Rust projects I have tend to have justifiably large dependencies, e.g. wasmtime or Slint. I don't think it's unreasonable to expect a whole GUI toolkit to have quite a few dependencies. I have yet to find any dependencies that I thought were ridiculous like leftpad.
We could definitely do with better tooling to handle supply chain attacks. Maybe even a way of (voluntarily) tying crate authors to verified real identities.
But I also wouldn't worry about it too much. If you a really worried, develop in a docker container, use a dependency cooldown, and whatever you do don't use cryptocurrencies on your dev machine.